An optical member is conventionally joined to a substrate as follows. Two or more glass substrates, such as an LCD, are successively transported at a given pitch in a horizontal direction. A strip-shaped polarization film is fed out and transported from a feed roll placed above a transportation path of the glass substrate. The polarizing film and an adhesive layer thereof are cut in a width direction perpendicular to a traveling direction in accordance with a length of the glass substrate in the traveling direction while a separation film joined to the adhesive layer of the polarizing film is left in the polarizing film transportation process. Thereafter, a piece of the polarizing film joint to the separation film is removed from the separation film by a separating device immediately before reaching a joining position to the glass substrate. The piece of the polarizing film is then aligned such that a cutting end face thereof in the traveling direction is parallel to an end face of the glass substrate in the traveling direction. The piece of the polarizing film fed out from an upper portion of the glass substrate is joined to the glass substrate while a roller as a joining device presses the piece of the polarizing film (see Patent Literature 1.)
[Patent Literature 1]
Japanese Patent Publication No. 2005-37416